I grew up with 2 yorkies. As a child I would tease the male constantly. Believe me the payback was brutal vicious little critter. But I never got more than a small bruise and omg I deserved so much more. I have had large breed dogs of all types for 50 years or more and my experience is that certain breeds are just psyco and it cannot be trained out. If you are using them for hunting fine, otherwise they have no business being able to roam free.